#macro LatinYear(year_)
  #if (int(year_) != year_)
    #error "oops, bad 'year'."
  #elseif (year_ < 1 | 3999 < year_)
    #error "oops, out-of-range 'year'."
  #end
  #macro __cvt(dgt_, s1_, s5_, s10_)
    #local units_ = concat(s1_,s1_,s1_);
    #local n_ = val(dgt_);
    #switch (n_)
      #case(0) #local t_ = ""; #break
      #range(1,3) #local t_ = substr(units_,1,n_); #break
      #case(4) #local t_ = concat(s1_,s5_); #break
      #case(5) #local t_ = s5_; #break
      #range(6,8) #local t_ = concat(s5_,substr(units_,1,n_-5)); #break
      #case(9) #local t_ = concat(s1_,s10_); #break
      #else #error "oops, \"cannot happen\" error in '__cvt()'."
    #end
    t_
  #end
  #local ystr_ = str(year_,0,0);
  #local s_ = "";
  #switch (strlen(ystr_))
    #case(4)
      #local s_ = concat(substr("MMM",1,val(substr(ystr_,1,1))),
                         __cvt(substr(ystr_,2,1),"C","D","M"),
                         __cvt(substr(ystr_,3,1),"X","L","C"),
                         __cvt(substr(ystr_,4,1),"I","V","X"));
      #break
    #case(3)
      #local s_ = concat(__cvt(substr(ystr_,1,1),"C","D","M"),
                         __cvt(substr(ystr_,2,1),"X","L","C"),
                         __cvt(substr(ystr_,3,1),"I","V","X"));
      #break
    #case(2)
      #local s_ = concat(__cvt(substr(ystr_,1,1),"X","L","C"),
                         __cvt(substr(ystr_,2,1),"I","V","X"));
      #break
    #case(1)
      #local s_ = __cvt(ystr_,"I","V","X");
      #break
    #else #error "oops, \"cannot happen\" error in 'LatinYear()'."
  #end
  s_
#end